Nexus 7 is straightforward build with two speakers and the sound is horrible for me, so I am looking for nice speakers that face out towards each side on the tablet. After trying various external brand names speakers, I find they are not good enough to hear. Then I note that Amazon sells a few different models of Razer speakers and I purchased Razer Ferox Mobile Gaming Speakers (RZ05-00500100-R3) last week.
Razer Ferox Mobile Gaming Speakers (RZ05-00500100-R3) features digitally enhanced amplifier efficiency and powerful bass. Easy to take it around in the carrying case. They also also come with a mini usb port and a usb charge wire.